Electrode support strap

ABSTRACT

A first portion receives and is attached to an electrode for an electron gun. Second portions extending from the first portion are adapted for attachment to a support. Each second portions has a protrussion from a surface thereof for contacting an adjacent strap of similar design.

United States Patent [191 Nestleroth [451 Dec. 24, 1974 ELECTRODE SUPPORT STRAP [75] Inventor: Paul Lavern Nestleroth, Lancaster,

[73] Assignee: RCA Corporation, New York, NY.

[22] Filed: July 11, 1973 [21] Appl. No.: 378,178 g [52] US. Cl 313/417, 313/254, 313/284, 313/292, 313/456 [51] Int. Cl HOlj 29/50, HOlj 29/02 [58] Field of Search 313/69 C, 70 C, 82 R, 253, 313/254, 256, 284, 285, 292, 417, 438, 451,

[56] References Cited UNITED STATES PATENTS 3,389,284 6/1968 Andrews 313/284 X 3,745,397 7/1973 Yamazaki et a1. 313/70 C Primary ExaminerAlfred E. Smith Assistant Examiner-E. R. LaRoche Attorney, Agent, or Firm-Glenn H. Bruestle; Dennis H. Irlbeck [5 7] ABSTRACT A firstportion receives and is attached to an electrode for an electron gun. Second portions extending from the first portion are adapted for attachment to a support. Each second portions has a protrussion from a surface thereof for contactingan adjacent strap of similar design.

8 Claims, 3 Drawing Figures ELECTRODE SUPPORT STRAP BACKGROUND OF THE INVENTION This invention relates to cathode-ray tubes and particularly to straps for supporting electron gun electrodes within a cathode-ray tube.

Cathode-ray tubes for use in color television usually include a screen of red, green and blue emitting phosphor lines or dots, electron gun means for exciting the screen, and an apertured mask interposed between the gun means and the screen. The gun means produces a separate electron beam for each color emitted by the screen. Each beam is blocked by the apertured mask from striking any color emitting phosphor except that of its associated color. Basically, the gun means for a three beam tube comprises, three cathodes for producing electrons and three sets of about five electrodes for accelerating, controlling and focusing each electron beam. The cathodes and the associated electrodes may be either in a delta formation or in-line in a flat plane. The electrodes are usually interconnected to a common support, such as glass rods, by straps which are welded directly to electrodes and have their ends partially embedded in the support material. In order to maintain similar electrodes for the adjacent electron beams at common potentials, the electrode straps are usually welded together at the ends that are embedded in the support. Such welding would pose no problem if the straps made surface to surface contact. However, it is often necessary in constructing the gun to angle the electrodes toward each other so that a certain degree of physical convergence is provided. Because of this angling, the electrode support straps contact each other in a rather random point to point fashion. If the straps are then welded together at a set location on the straps, a lever arm is formed between the weld position and the contact location which may eventually cause failure of the weld during subsequent handling of the gun.-

SUMMARY OF THE INVENTION An electrode strap for use in an electron gun includes a first portion adapted to be attached to the electrode and at least one second portion extending from the first portion. The second portion is adapted for attachment to a support. The second portion has a protrusion from a surface thereof for contacting an adjacent strap of similar design.

IN THE DRAWINGS FIG. 1 is a perspective view of an electrode support strap embodying the present invention;

FIG. 2 is a perspective view of an electrode assembly utilizing three of the straps of FIG. ,1; and

FIG. 3 is a side view taken at lines 3-3 of FIG. 2.

DETAILED DESCRIPTION A single electrode support strap 10, shown in FIG. 1, includes a curved central section 12, adopted to conform to the shape of a cylindrical electrode. Two flanges I4 and 16 extend from the central section 12 and form a 120 angle with each other. Each flange is adapted to be imbedded in supporting rods of an electron gun. Curved interface sections 18 and interconnect the flanges 14 and 16, respectively, to the central section 12. The flanges l4 and 16 have small projections or pointed protrusions 22 and 24, respectively, located near the outer edges and at opposite corners of the strap 10. The protrusions 22 and 24 may be formed by embossing each flange, by adding some material, such as by welding, or by any other known method.

The purpose of using pointed protrusions at the ends of the flanges is to ensure that the point of contact between adjacent flanges, when assembled into an electron gun, will always be uniform and predictable. The fulfillment of this purpose can be seen in the illustrations of FIGS. 2 and 3 wherein the only point of contact between adjacent straps is at the protrusion on one of the straps. FIG. 2 shows three electrodes 26, 28 and 30 mounted in a delta relationship by three support straps 32, 34 and 36, respectively. Each of these straps is identical with the strap 10 of FIG. 1. All three of the electrodes are positioned to converge at a point to the lower left in front of the paper. Therefore, a single protrusion on each strap makes contact with a flat surface of an adjacent strap as shown in FIG. 3. It also should I be noted that not only are the straps interchangeable but they are also reversible since the strap design is symmetrical.

During assembly of the electrodes and straps, suitable welding equipment, known in the art, may be utilized to weld the straps together at the locationsof the projections. Since the protrusions are always located at the same position on the strap and welding may be repeditively performed at this position, the point of contact between straps will always be the point of weld. Thus, the reliability and production yields of an electrode-strap assembly having straps constructed in accordance with the present invention is increased since any twisting action transferred to the electrode is minimized and electrode alignment is improved.

I claim: I

1. An electrode strap for use in an electron gun comprising: l

a first portion for receiving and attachment to an electrode of said electron gun, and

at least one second portion extending from said first portion adapted for attachment to a support, said second portion having a pointed protrusion from a surface thereof for providing a single point contact with an adjacent strap of similar design in an assembled gun.

2. The electrode strap as defined in claim 1, including two second portions each positioned on opposite sides of said first portion and each having a pointed protrusion from a surface thereof.

3. The electrode strap as defined in claim 2, wherein said two second portions form a angle with each other. v

4. The electrode strap as defined in claim 3, including said first portion being partially circular in shape conforming to a cylindrical electrode.

5. An electrode strap for use in an electron gun comprising:

a first portion for receiving and attachment to an electrode of said electron gun, and

two second portions positioned on opposite sides of said first portion and extending therefrom, at least one of said second portions having a pointed pro trusion extending from a surface thereof for providing a single point contact with a strap of similar design, said protrusion being located near an outer edge of the second portion remote from said first portion.

6. The electrode strap as defined in claim 5, including both second portions having pointed protrusions and said protrusions being located at diagonally opposite corners of said strap.

7. An electrode strap for use in an electron gun comprising:

a first portion for receiving and attachment to an electrode of said gun, said first portion being partially cylindrical in shape conforming to a cylindrical electrode attachable to a front surface of said strap, and

two second portions extending'from opposite sides of said first portion, the front surfaces of said second portion forming a 120 angle with each other, each second portion having at least one embossed protrusion extending from a back surface thereof, at least one protrusion on each second portion being located at diagonally opposite corners of said strap,

whereby upon assembly of similar straps and cylindri- 8. An electrode strap for use in an electron gun coinprising:

a first portion for recieving and attachment to an electrode of said electron gun, and

two second portions positioned on opposite sides of said first portion and extending therefrom.

both second portions having embossed protrusions and said protrusions being located near an outer edge of the second portion remote from said first portion and at diagonally opposite corners of said strap for contacting a strap of similar design when assembled into an electron gun. 

1. An electrode strap for use in an electron gun comprising: a first portion for receiving and attachment to an electrode of said electron gun, and at least one second portion extending from said first portion adapted for attachment to a support, said second portion having a pointed protrusion from a surface thereof for providing a single point contact with an adjacent strap of similar design in an assembled gun.
 2. The electrode strap as defined in claim 1, including two second portions each positioned on opposite sides of said first portion and each having a pointed protrusion from a surface thereof.
 3. The electrode strap as defined in claim 2, wherein said two second portions form a 120* angle with each other.
 4. The electrode strap as defined in claim 3, including said first portion being partially circular in shape conforming to a cylindrical electrode.
 5. An electrode strap for use in an electron gun comprising: a first portion for receiving and attachment to an electrode of said electron gun, and two second portions positioned on opposite sides of said first portion and extending therefrom, at least one of said second portions having a pointed protrusion extending from a surface thereof for providing a single point contact with a strap of similar design, said protrusion being located near an outer edge of the second portion remote from said first portion.
 6. The electrode strap as defined in claim 5, including both second portions having pointed protrusions and said protrusions being located at diagonally opposite corners of said strap.
 7. An electrode strap for use in an electron gun comprising: a first portion for receiving and attachment to an electrode of said gun, said first portion being partially cylindrical in shape conforming to a cylindrical electrode attachable to a front surface of said strap, and two second portions extending from opposite sides of said first portion, the front surfaces of said second portion forming a 120* angle with each other, each second portion having at least one embossed protrusion extending from a back surface thereof, at least one protrusion on each second portion being located at diagonallY opposite corners of said strap, whereby upon assembly of similar straps and cylindrical electrodes to provide physical convergence of the electrode central longitudinal axes in an electron gun, a protrusion of one strap makes a single point contact with a back surface of another strap.
 8. An electrode strap for use in an electron gun comprising: a first portion for recieving and attachment to an electrode of said electron gun, and two second portions positioned on opposite sides of said first portion and extending therefrom, both second portions having embossed protrusions and said protrusions being located near an outer edge of the second portion remote from said first portion and at diagonally opposite corners of said strap for contacting a strap of similar design when assembled into an electron gun. 